Image-reading device having configurable multi-mode illumination sequences and monochrome color image capture sequences and related methods

ABSTRACT

An image-reading device, such as optical code readers used in retail environments to scan objects, is configured to select from various operational modes. The operational modes are selected based on an application of the image-reading device, such as optical code identification or image recognition. Red, white, and other color light sources are activated in patterns corresponding to an illumination sequence of the selected operational mode, while imagers are activated to capture an image based on an exposure pattern of the selected operational mode. Further, a repeating series of light pulses having different portions of light is provided. Various imagers are configured to capture images over one of the portions. This allows an operator to perceive one continuous light pattern, yet allows various imagers to capture an image under different light conditions used for different applications of the image-reading device.

BACKGROUND

Image-reading devices, such as those used by store checkout attendantsare used to identify objects. Some image-reading devices identify andcapture optical codes, such as two-dimensional codes (e.g., QuickResponse (QR) codes), one-dimensional bar codes, as well as high densitycodes, Dot codes, watermarking (e.g., Digimarc), optical characterrecognition (OCR), and other visual code and image recognitiontechniques for identifying an object. For example, upon identifying andcapturing the optical codes, the optical codes are decoded to provideinformation represented by the optical code. In the scenario of thestore checkout attendant, the optical code is then processed to provideinformation about an associated object. Bioptic style image-readingdevices, those that identify and capture objects along two spatialplanes, are popular for high-volume applications because these devicescan identify objects across more spatial orientations. Thus, the need tomanipulate the object's spatial orientation is reduced.

While some image-reading devices are capable of using ambient light asan illumination source, many conventional image-reading devices have alight source that illuminates an area. The light source helps theimage-reading device more clearly identify the object within the area.The inventors have appreciated various improvement to illuminationsystems for image-reading devices.

SUMMARY

At a high level, aspects described herein relate to an image-readingdevice having a multi-mode configuration. The image-reading device isconfigured to select from one of several operational modes based on aselection event, such as a manual input or automatically based on theintensity of available ambient light, the speed of an object movingthrough an area, or an object weight being detected, or with apre-determined algorithm.

A first operational mode that can be selected includes a firstillumination sequence having continuous activation of a light sourcebefore a first triggering event and a first exposure sequence havingcontinuous activation of an imager before the first triggering event. Asecond operational mode includes a second illumination sequence havingtemporary activation of the light source before a second triggeringevent and a second exposure sequence having temporary activation of theimager after the second triggering event. A third operational modeincludes a third illumination sequence having temporary activation ofthe light source after a third triggering event and based on anintensity of ambient light, and a third exposure sequence havingtemporary activation of the imager after the third triggering event.

When the operational mode is selected, a controller of the image-readingdevice activates a light source and an imager to capture an image basedon an illumination sequence and an exposure sequence of the selectedoperational mode. The controller can activate the light source or theimager before or at the occurrence of a triggering event based on theselected operational mode.

Another embodiment of the technology includes activating light sourcesso that a repeating series of light pulses is produced. The repeatingseries of light pulses includes portions of red, white, and ambientlight.

Different imagers associated with the image-reading device can beactivated to capture an image during one of the light pulse portions. Inthis way, images under the red, white, and ambient lighting conditionscan be captured. The different captured images can be used for differentapplications, as each color or ambient condition has benefits forparticular applications. Short red pulses and short white pulses aregood for image identification and optical code reading. Longer whitepulses are good for object recognition. Ambient lighting is good forreading objects on reflective or glossy surfaces, such as an opticalcode or other image displayed on a mobile device screen.

This summary is intended to introduce a selection of concepts in asimplified form that is further described in the Detailed Descriptionsection of this disclosure. The Summary is not intended to identify keyor essential features of the claimed subject matter, nor is it intendedto be used as an aid in determining the scope of the claimed subjectmatter. Additional objects, advantages, and novel features of thetechnology will be set forth in part in the description that follows,and in part will become apparent to those skilled in the art uponexamination of the disclosure or learned through practice of thetechnology.

BRIEF DESCRIPTION OF THE DRAWINGS

The present technology is described in detail below with reference tothe attached drawing figures, wherein:

FIG. 1 is an example image-reading device suitable for use with aspectsof the described technology, in accordance with an aspect descriedherein;

FIG. 2 is an example computing device configured to operate theimage-reading device of FIG. 1 , in accordance with an aspect describedherein;

FIG. 3 illustrates an example multi-mode configuration engine suitablefor use with an image-reading device, in accordance with an aspectdescribed herein;

FIG. 4 is an example timing diagram for wireless synchronization oflight sources, in accordance with an aspect described herein;

FIG. 5 is an example timing diagram for wired synchronization of lightsources, in accordance with an aspect described herein;

FIG. 6 is a timing diagram illustrating an example first operationalmode, in accordance with an aspect described herein;

FIG. 7 is a timing diagram illustrating an example second operationalmode, in accordance with an aspect described herein;

FIG. 8 is a timing diagram illustrating an example third operationalmode, in accordance with an aspect described herein;

FIG. 9A is a timing diagram for providing different light pulses fordifferent applications of an image-reading device, in accordance with anaspect described herein;

FIG. 9B is a circuit diagram of an example hardware device suitable forproviding the different light pulses of FIG. 9A, in accordance with anaspect described herein;

FIG. 10 is a timing diagram illustrating a software process forproviding different light pulses for different applications of animage-reading device, in accordance with an aspect described herein;

FIG. 11 is a block diagram illustrating an example method of multi-modeillumination and image capture using an image-reading device, inaccordance with an aspect described herein;

FIG. 12 is a timing diagram illustrating a repeating series of lightpulses and exposure periods, in accordance with an aspect describedherein; and

FIG. 13 is a block diagram illustrating an example method for performingillumination and exposure using a repeating series of light pulses, inaccordance with an aspect described herein.

DETAILED DESCRIPTION

As noted in the Background, image-reading devices (e.g., optical codereaders) may illuminate an area to better identify and capture an imageof an object. These conventional image readers typically have brightlights used for the illumination. Combining the bright lights withmultiple plane readers, like bioptic style image-reading devices, canresult in some illumination that is observed by an operator. This can bedistracting and sometimes reduces the overall user-friendliness whenoperating the image-reading devices.

Further, illumination types and sources can be different depending onthe image reader's application. For instance, an image-reading devicelocated near a window in a store might have enough ambient light duringthe day to identify and capture images of objects. However, at night,the image-reading device may require additional illumination toeffectively identify and capture images of the same objects, especiallywhen the timing opportunity to capture such images is narrow. Furtherstill, the image-reading device might be used for differentapplications, such as capturing an image of a barcode and decoding theinformation versus capturing an image of a piece of fruit to identifythe type of fruit. Here, enhanced optical recognition and illuminationtechniques help to better identify the fruit, but the additional lightfrom these techniques may not be necessary for all other applications,such as capturing an image of the barcode.

Conventional technologies lack techniques that change illumination andcapture modes to fit a particular application or condition. Because ofthis, the image-reading device placed near a window might useillumination techniques needlessly during the day, as the illuminationis needed only during nighttime hours. Similarly, the image-readingdevice might be configured to emit a longer, more intense form ofillumination that is beneficial when capturing an image to identifyobjects like the piece of fruit, but this same illumination is notnecessarily needed when capturing a barcode image. In both scenarios,the image-reading device is not operating efficiently, and it could beneedlessly exposing operators and others nearby to bothersomeillumination.

The technology of this disclosure solves some of the problems that arecurrently experienced with the conventional technology. In particular,some aspects of the disclosed technology provide a configurablemulti-mode illumination. The various modes can be configured for thespecific application or condition. For instance, one mode may be usedfor capturing images of a barcode or other optical code for decoding,while another mode is used to capture an image of an object (a produceitem, fruit, vegetable, etc.) for item identification. Similarly, onemode may be used during the day when there is enough ambient lightpresent for sufficient image capture, while another mode is used whenambient light is not sufficient. Moreover, the configurable multi-modeillumination that will be further described provides technology thatallows an operator to continually use an image-capture device whenpresented with different application needs, including illumination for abarcode versus illumination for object identification and recognition,instead of stopping between applications or switching to a differenthardware device, such as a portable hand scanner.

Additional aspects of the technology provide illumination schemes tocapture monochrome, color, or ambient light images under active orambient illumination. This provides a way to take red, white, andambient light exposures, and allow combined white and ambient exposuresas they are needed. These techniques provide a mechanism by which theimage-reading device has access to each exposure type that is best foreach application, meaning that the exposure types are accessible withineach frame time. This reduces the outside input needed to operateimage-scanning-device technology that utilizes various illuminationtechniques depending on the application. At the same time, theillumination schemes appear consistent when observed by the operator. Bymaking the illumination consistent, the observer acclimates to theparticular illumination. This desensitizes the operator to theillumination, making the illumination less obtrusive and graduallyimperceptible.

One example method that realizes these benefits includes a configurablemulti-mode illumination and an image capture method. Under this method,an image-reading device utilizes at least one of a plurality ofoperational modes, where each operational mode defines an illuminationsequence and an exposure sequence. Here, the illumination sequenceprovides instructions to activate a light source to emit light, whilethe exposure sequence provides instructions for capturing an image usingan imager. An operational mode can be selected based on a particularapplication of the image-reading device, and may be selected based on aparticular triggering event. Thus, the image-reading device can be usedfor various applications, such as reading an optical code or capturingan image of an object to identify and recognize the object, and invarious conditions, such as low-ambient light conditions andhigh-ambient light conditions. Conventional systems are static andcannot be configured to optimally perform over the differentapplications and conditions.

Example operational modes that may be selected include a first mode thathas a continuously active light and has a continuously active imager.The continuous light is beneficial because it does not appear toflicker, which reduces an operator's perception of the light. Further,the continuous image capture is beneficial in particular use scenarioswhere there is a higher volume of object recognition relative to taskssuch as reading an optical code.

A second example operational mode includes temporarily activating thelight source and the imager in response to a triggering event, such asdetecting an object weight, a speed of the object through the area overwhich the imager captures the image, a manual input by the operator,comparing an ambient light to an illumination threshold, or any othersuch triggering event and combinations thereof. This mode has benefitsover conventional systems because activation of the light is temporaryand based on a triggering event. In this way, the operator may notexperience a constant illumination, but rather, the light can beactivated when needed based on the application.

A third operational mode includes temporarily activating the lightsource and the imager in response to the triggering event, whereactivation of the light is also based on an intensity of ambient light.This mode also has benefits over conventional systems because the lightcan be activated when there is not enough ambient light. In this way,the user experiences the additional light emitted by the light sourcewhen the light source is needed. This mode is also more efficient thanconventional systems because it uses ambient light when the ambientlight is suitable for the particular application, rather than constantlyactivating the light source, including activating the light sourceduring times it is not needed due to the availability of ambient light.

Another method that achieves such benefits over conventional systemsuses light pulses that allow red, white, and ambient exposures to betaken, and allows for combined white and ambient exposures when needed.Conventional systems do not utilize red, white, and ambient light.However, each type of light has benefits. The red light may providecertain benefits for recognition of optical codes, the white light mayprovide certain benefits for image recognition, and the ambient lightmay provide certain benefits for imaging objects with reflective orglossy surfaces, such as objects within plastic or displayed on thescreen of a mobile device.

This example method includes using pulses of light in a repeatingseries, where each pulse may be the same. That is, each pulse has aportion of red light, a portion of white light, and a portion of thepulse that is formed of ambient light. The red and white light can beemitted through activation of one or more light sources, while theambient light may be provided from light emitted by a light source thatis not part of the image-reading device. To capture images using the redlight, white light, or the ambient light, a first imager is activatedfor exposure period corresponding to one of the portions. A secondimager is activated for different exposure period that corresponds toanother portion. In this way, the image from the first imager can beused for a particular application, such as reading an optical code,performing image recognition, or reading an image displayed on a mobiledevice, while the image from the second imager is used for a differentapplication.

By using pulses of light in a repeating series, an operator observes thesame pulse pattern, even though the image-reading device is usingdifferent portions of the light pulse for different applications. Thishelps keep the operator from observing random changes in the light asthe application changes, and thus makes it more likely that the operatorwill acclimate to the light pulses.

The aspects previously described are provided as examples to aid inunderstanding the technology and to show the benefits that can beattained through practice of the technology. These aspects are onlyexamples that may be derived from the description that follows, whichreferences the figures.

Operating Environment

FIG. 1 provides an example image-reading device 100 suitable for usewith aspects of the disclosed technology. FIG. 2 provides an examplecomputing device 200 configured to operate image-reading device 100.Together, FIG. 1 and FIG. 2 provide an example operating environment inwhich aspects of the disclosed technology may be employed.

Referring first to FIG. 1 , image-reading device 100 is a biopticoptical code reader that comprises base 102 that includes horizontalsection 104 and vertical section 106. In the example illustrated,horizontal section 104 includes horizontal window 108, while verticalsection 106 includes vertical window 110. Horizontal window 108 andvertical window 110 are translucent or transparent to light. Horizontalsection 104 and vertical section 106 may be included within base 102.

While not illustrated, horizontal section 104 can be included as part ofa scale provided at base 102. When an object is placed within the areaof base 102 on top of horizontal section 104, the scale detects theobject's weight and provides this to a controller.

Image-reading device 100 comprises one or more top-down readers, such asfirst top-down reader 112 and second top-down reader 114. Top-downreaders may comprise a light source. In some cases, the light sourcesare inside a top-down reader housing having a top-down reader window. Asan example, in FIG. 1 , first top-down reader 112 is shown having firsttop-down reader housing 116 that comprises first top-down reader window118, which conceals first top-down reader light source 120A. Similarcomponents of second top-down reader 114 are not labeled or illustratedfor clarity.

In general, any number of light sources, such as first top-down readerlight source 120, may be included as part of image-reading device 100and provided at any location, whether physically attached or remote. Forexample, image-reading device 100 further includes light sources 120Band 120C. Generally, light sources comprise an emitter configured toemit light of any wavelength. Light sources suitable for use are furtherdiscussed with reference to FIG. 2 . Accordingly, light sources 120A-Cand any other light sources that may be included as part ofimage-reading device 100 may emit white, infrared, ultraviolet, red,blue, or green light, or any combination or sequence thereof, amongother light colors or wavelengths.

Image-reading device 100 includes one or more imagers, such as imagers122A-D illustrated within various locations of image-reading device 100.This may include one or more monochrome imagers, one or more colorimagers, or any combination thereof. For instance, imagers may be withinbase 102, such as imagers 122B-D, or within a top-down reader, such asimager 122A in first top-down reader 112, among other locations. Ingeneral, an imager may include an image sensor and a lens that provide afield of view within which an image of an object may be captured bydetecting light or another form of electromagnetic radiation, andconverting it into communication signals providing associated imageinformation. It should be understood that more or fewer imagers may beprovided in each of the horizontal section 104 or vertical section 106of the base 102 or the top down readers 112, 114 and at differentlocations than those specifically shown in FIG. 1 . Imagers may includemonochrome imagers, color imagers, or a combination thereof throughoutthe image-reading device 100. Some imagers are described in more detailwith reference to FIG. 2 .

Continuing with FIG. 1 , image-reading device 100 further comprises oneor more object detectors. Object detectors discussed with reference toFIG. 2 are suitable for use as the object detectors illustrated in FIG.1 . It will be understood that various object detection techniques areavailable, and that the hardware elements illustrated in FIG. 1 aremeant to provide one example and are not intended to be limiting in anysense. The one or more object detectors shown in FIG. 1 use a lightdetection technique to determine whether an object is within the area ofimage-reading device 100, which will be further discussed with referenceto FIG. 2 . However, in this example, the one or more object detectorscomprise light emitters 124A and 124B, and light detectors 126A and126B.

Image-reading device 100 may comprise one or more photosensors disposedat any location. Image-reading device 100 is illustrated havingphotosensors 128A and 128B. Here, photosensor 128A is disposed at base102, and photosensor 128B is disposed at second top-down reader 114.Photosensors generally detect light and may determine an intensity ofthe light. Some photosensors determine an intensity of particularwavelengths of light, such as wavelengths associated with white, red,blue, and green lights. Photosensors are further described withreference to FIG. 2 . As noted in the discussion related to FIG. 2 ,imagers may act as photosensors as well, meaning that an imager can alsobe used to detect light or determine the intensity of light. Thus, someapplications of image-reading device 100 may not include photosensors.Instead, image-reading device 100 may rely on the imagers to performthese functions, instead. Both embodiments, and any combinationsthereof, are intended to be within the scope of this disclosure.

It should be understood that FIG. 1 has been provided only as an exampleof a type of image-reading device suitable for use with the technology.It will be recognized that the technology can be employed in otherdevices, such as mounted devices or handheld units. Other devices mayinclude additional or fewer components, or comprise other arrangementsof components.

An additional example image-reading device includes the data readerdescribed in U.S. Pat. No. 10,049,247 that granted from U.S. applicationSer. No. 15/292,037 filed with the United States Patent and TrademarkOffice on Oct. 12, 2016, the contents of which are expresslyincorporated herein by reference in their entirety. Yet another exampleimage-reading device sufficient for use is described in U.S. Pat. No.9,305,198 that granted Apr. 5, 2016 from U.S. application Ser. No.13/911,854 filed with the United States Patent and Trademark Office onJun. 6, 2013, the contents of which are expressly incorporated herein byreference in their entirety.

Turning now to FIG. 2 , an example computing device 200 suitable for andconfigured to operate image-reading device 100 of FIG. 1 is provided.Computing device 200 is one example of a suitable computing environmentand is not intended to suggest any limitation as to the scope of use orfunctionality of the technology. Computing device 200 should not beinterpreted as having any dependency or requirement relating to any oneor combination of components illustrated.

Some aspects of the technology of the present disclosure may bedescribed in the general context of computer code or machine-useableinstructions, including computer-executable instructions such as programmodules, being executed by a computer or other machine, such as apersonal data assistant or other handheld device. Generally, programmodules including routines, programs, objects, components, datastructures, etc. refer to code that perform particular tasks orimplement particular abstract data types. The technology may bepracticed in a variety of system configurations, including hand-helddevices, consumer electronics, general-purpose computers, more specialtycomputing devices, etc. The technology may also be practiced indistributed computing environments where tasks are performed byremote-processing devices that are linked through a communicationsnetwork. In a specific implementation, the technology is practiced in animage-reading device, such as image-reading device 100 in FIG. 1 . Inone aspect, computing device 200 may be a special-purpose computingdevice configured to be implemented with an image-reading device.

With continued reference to FIG. 2 , computing device 200 includes bus202 that directly or indirectly couples the following devices: memory204, one or more processors 206, one or more presentation components208, input/output ports 210, input/output components 212, andillustrative power supply 214. Bus 202 represents what may be one ormore busses (such as an address bus, data bus, or combination thereof).

Although the various blocks of FIG. 2 are shown with lines for the sakeof clarity, in reality, delineating various components is not so clear,and metaphorically, the lines would more accurately be grey and fuzzy.For example, one may consider a presentation component such as a displaydevice to be an I/O component. Additionally, processors can have memory.It will be appreciated that this is the nature of the art. As such, itis reiterated that the diagram of FIG. 2 is merely illustrates anexample computing device that can be used in connection with aspects ofthe present technology.

Computing device 200 typically includes a variety of computer-readablemedia. Computer-readable media can be any available media that can beaccessed by computing device 200 and includes both volatile andnonvolatile media, removable and non-removable media. By way of example,and not limitation, computer-readable media may comprise computerstorage media and communication media.

Computer storage media includes volatile and nonvolatile, removable andnon-removable media implemented in any method or technology for storageof information such as computer-readable instructions, data structures,program modules or other data. Computer storage media includes, RAM,ROM, EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (DVD) or other optical disk storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium that can be used to store the desired informationand can be accessed by computing device 200. Computer storage media isnon-transitory and excludes signals per se.

Communication media typically embodies computer-readable instructions,data structures, program modules or other data in a modulated datasignal such as a carrier wave or other transport mechanism and includesany information delivery media. The term “modulated data signal” means asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in the signal. By way of example,communication media includes wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, RF,infrared, Bluetooth, and other wireless media. Combinations of any ofthe above should also be included within the scope of computer-readablemedia.

Memory 204 includes computer storage media in the form of volatile ornonvolatile memory. The memory may be removable, non-removable, or acombination thereof. Example hardware devices include solid-statememory, hard drives, optical-disc drives, etc.

Some aspects of the technology provide for illumination driver 216. Ingeneral, illumination driver is stored on memory 204 and is suitable forapplying signals to a light source, including various light sources.That is, illumination driver 216 serves to allow one or more processors206 to activate or otherwise control the light source. Accordingly,illumination driver 216 drives the light source by providing a series ofpulses having a given pulse width. In general, increasing the pulsewidth increases the time the light source is activated during anillumination pulse cycle (e.g., by increasing the duty cycle of anillumination waveform).

Computing device 200 includes one or more processors 206 that read datafrom various entities such as memory 204 or I/O components 212.

Some aspects of the technology implement or are implemented bycontroller 218. Controller 218 can include memory, such as memory 204,and one or more computer processors, such as processors 206, executinginstructions that cause the processors to perform operations. Ingeneral, controller 218 controls and coordinates the operation of otherdevices, including various I/O components 212, such as object detector220, imager 222, and light source 224.

Object detector 220 generally detects the presence of an object. Objectdetector 220 can be configured to detect the presence of the object thatis located in, that enters, or that is removed from a particularlocation. One example technology suitable for use as object detector 220is a laser detector. Here, light is emitted from a laser emitter. Thelight is detected by a laser detector. When the object enters the area,it blocks the light, and the laser detector sends a signal to controller218 that the light is not being detected. Controller 218 interprets thissignal as the object being located in the area over which the light isemitted by the laser emitter. This is just one example that can be used;however, it will be recognized that other technologies are also suitableas an object detector, such as mechanical technologies that physicallyinteract with the item or object, or another optical technology thatsenses the presence of the item or object, for instance opticaltechnology that senses the presence from the image data itself. Inanother example, a combination of an imager and light source may serveas object detector 220. Light source 224 may be operable by illuminationdriver 216.

Imager 222 generally captures an image. Imager 222, when activated,takes an image from light received via a lens focusing the light ontoimager 222. Imager 222 may be configured to take an image of an area andany object located in the area of its field of view. Imager 222 mayreceive light, ambient or from a light source of an image-readingdevice, and form electronic image data representative of the image. Someaspects provide the image data to a digital signal processor or otherdecoder interfaced to imager 222 in order to read the image data. Imager222 may comprise a wide range of image-sensing technologies that convertoptical images of various wavelengths, including those within thevisible spectrum. In one example, imager 222 is a charged-coupled device(CCD) or complementary metal-oxide semiconductor (CMOS) imager. Aspreviously noted, some components are discussed separately to aid indescribing the technology. However, some components can be separatecomponents, or integrated into the same hardware. For instance, imager222 may also serve to function as object detector 220.

Light source 224 comprises hardware elements that emit forms ofelectromagnetic radiation. Generally, these will be wavelengthsassociated with the visible light spectrum, such as wavelengths aboutequal to or between 380 nm and 750 nm. Other hardware elements intendedto be included may emit electromagnetic radiation outside of thesewavelengths, as these wavelengths can still be detected by detectors,even if there are not visible to the human eye. One such example isinfrared electromagnetic radiation having wavelengths about equal to orbetween 700 nm to 1 mm, while another is ultraviolet having wavelengthsabout equal to or between 10 nm to 400 nm. Unless otherwise stated,light sources can emit or be configured to emit any wavelength ofelectromagnetic radiation, including any wavelength within the visiblespectrum or infrared spectrum. In specific implementations, lights emitwavelengths associated with visible white light, red light, blue light,green light, or any combination or sequence thereof. Light source 224may include any one of or combination of suitable light sources,including light emitting diodes (LEDs), flash strobes, incandescentlamps, fluorescent lamps, halogen bulbs, and so forth.

Photosensor 226 generally detects electromagnetic radiation. Photosensor226 can detect electromagnetic radiation, including that within thevisible light spectrum, and generate a current based on the intensity ofthe detected electromagnetic radiation. Photosensor 226 iscommunicatively coupled to controller 218. Controller 218 receives thegenerated current from photosensor 226 and processes it to determine theintensity of the light detected by photosensor 226. Photosensor 226 candetect light generated by components of an image-reading device, such asimage-reading device 100 of FIG. 1 , or ambient light emanating fromsources other than the image-reading device. One example suitable foruse is a photodiode. In an aspect, an imager can act as a photosensor,such as photosensor 226 in addition to or in lieu of performing otherfunctions of the imager.

Presentation component 208 presents data indications to a user or otherdevice. Examples of presentation components suitable for use aspresentation component 208 include a display device, speaker, printingcomponent, vibrating component, and the like. One specific presentationcomponent included within presentation component 208 is a touch screendisplay. The touch screen display further acts as an I/O component thatcan be included within I/O component 212. Here, the touch screen displaycan provide a graphical user interface having an input area that allowsan operator to manually select a particular option, including aconfiguration option. Using this method, the operator can manuallyprovide an input to controller 218 indicating to the controller tochange a mode of operation.

I/O ports 210 allow computing device 200 to be logically coupled toother devices including I/O components 212, some of which may be builtin. Illustrative components include a microphone, joystick, game pad,satellite dish, scanner, printer, wireless device, etc. One I/Ocomponent that is included within I/O components 212 is a button that,when engaged by an operator, sends a signal to controller 218, whichcontroller 218 interprets and changes an operational mode in accordancewith the received signal.

Configurable Multi-Mode Illumination and Image Capture

As previously discussed, an image-reading device, such as imagereading-device 100 of FIG. 1 , may be configured to provide variousoperational modes. Each of the different operational modes may bebeneficial because many image-reading devices are used for differentapplications, and some operational modes may perform relatively betterfor a particular application or situation. Further, the variousoperational modes can be initiated to increase the efficiency of theimage-reading device, while at the same time, making the device moreuser friendly.

In some implementations, configurable operational modes are performedusing an image-reading device having one or more top-down readers, whichmay include light sources or imagers, among other components. A top-downreader can be configured to operate with a base, such as those exampleimage-reading devices previously described. Top-down readers can beconfigured to work with any computing device, including a point-of-salecomputer.

FIG. 3 illustrates an example multi-mode configuration engine 300. Ingeneral, multi-mode configuration engine 300 can be employed to providethe technology with configurable operational modes.

Multi-mode configuration engine 300 is illustrated as havingsynchronization component 302, mode selector 304, light activator 306,and imager activator 308. Other arrangements and elements (e.g.,machines, interfaces, functions, orders, and groupings of functions,etc.) can be used in addition to or instead of those shown, and someelements may be omitted altogether. Further, many of the elementsdescribed herein are functional entities that may be implemented asdiscrete or distributed components or in conjunction with othercomponents, and in any suitable combination and location. Variousfunctions described herein as being performed by one or more entitiesmay be carried out by hardware, firmware, or software. For instance,various functions may be carried out by a processor executinginstructions stored in memory. Various functions may be carried out by acontroller of an image-reading device, such as those image-readingdevices previously discussed.

When using the top-down reader in conjunction with the base forillumination and exposure, it may be beneficial to synchronizeactivation of light sources between the base and the top-down reader.Such synchronization may be carried out by synchronization component 302of multi-mode configuration engine 300.

Synchronization component 302 is configured to synchronize the timing ofactivation light sources or imagers located in a top-down reader and abase. It will be recognized that synchronization can be performed forlight sources positioned at any location of an image-reading device. Twomethods that can be employed by synchronization component 302 areprovided as examples and illustrated in FIGS. 4-5 .

FIG. 4 illustrates an example timing diagram 400 for wirelesssynchronization of light source between the base and the top-down readeror another remote reader. In this particular example, a red pulse beingemitted by a red light source, such as a red LED, is located in the baseof the image-reading device. A white pulse is being emitted from a whitelight source, such as a white LED, is located in the top-down reader. Animager is also provided at the top-down reader to capture images. Itwill be understood that a different arrangement of components may beused, and timing diagram 400 would be adjusted accordingly. In oneexample, the wireless synchronization includes synchronizing timingusing a photosensor in addition to or in lieu of an imager.

Wirelessly synchronizing the light sources and imagers may provide amechanism by which the technology can utilize a wireless top-down readeror other remote device, while maintaining proper timing betweenactivation of the light sources relative to the imagers for capturingimages. That is, wireless synchronization may provide a way to activatelight sources in a particular pattern and capture images using an imagerat times coinciding to the light source pattern. Thus, for instance, thetiming is synchronized such that an imager can be activated to capturean image over an exposure period, during which a light is also beingactivated, even when the light source and the imager are remote and notphysically connected by a direct-wired connection. As such, where animager is located in the base of an image-reading device and a lightsource is located in a wirelessly connected top-down reader, or viceversa, the timing of the imager activation accurately coincides with thetiming of the light source activation. As such, light pulses, such asred light pulses, may be programmed to occur during the time in whichimagers are used to capture images, such as monochrome imagers forcapturing images during red light pulses (e.g., for barcode decoding).Moreover, the synchronization may be applied to different light sourcesas well. Thus, the activation of remote light sources, such as those ina base and those in a top-down reader, can be timed to provide aparticular light sequence or pattern. One example pattern includesimmediate activation of a white light source after activating a redlight source, where the red light source and the white light source arewireless remote from one another.

As noted, timing diagram 400 illustrates one example of synchronizingremote imagers and light sources. In this specific case, the red lightsource is located in the base, while an imager and a while light sourceare located in a top-down reader. To illustrate the synchronization,timing diagram 400 includes time 402 represented horizontally andincreasing moving from left to right. Row 404 illustrates anillumination sequence for a red light source positioned at the base(e.g., in the horizontal or vertical portions) and pulsed at 80 Hz. Thered light source emits red light pulses when activated. Red light pulses406A and 406B are labeled as examples to illustrate the relative timingof the red light pulses of row 404. The red light pulses continueindefinitely, as illustrated using ellipses 408A and 408B, continuing tored light pulse 406N, which represents any number of red light pulses.

Row 410 illustrates activation of the imager. Exposure periods 412A and412B are labeled as examples, and are intended to illustrate the timesover which the imager is activated and detecting the red light pulses.Activation of the imager continues indefinitely, as illustrated usingellipses 414A, and continuing to exposure period 412N, which representsany number of exposure periods. The imager here is activated at the samerate the red light source is pulsed, which is 80 Hz in this example.Ellipsis 414B illustrates the imager is not detecting the red lightpulses during a second period of time, further discussed below. In anexample where the photosensor is used, exposure periods, such asexposure periods 412A and 412B comprise the time during which thephotosensor detects the red light pulses.

Row 416 illustrates a timing sequence of a field programmable gate array(FPGA) programmed to measure the red light pulses captured by the imagerduring the exposure periods. In this example, the FPGA clock measuresthe red light pulses, such as red light pulses 406A-N. The FPGA clock inthis example can be configured to measure the red light pulses at afrequency of 2 MHz. This is just one example, and other frequency ratesmay be used, including programming the FPGA at higher frequency rates toincrease the accuracy of the synchronization. The frequency rate isillustrated in row 416 using an indefinite frequency illustrated bypulses 418A through 418N and ellipses 420A and 420B. By programming theFPGA to measure the red light pulses captured by the imager during theexposure periods using a frequency less than the frequency of the lightsource activation and the exposure period, the time over which the redlight source is pulsed during imager activation can be measured.Synchronization of the imager and the red light source may be performedby adjusting the phase of the red light pulses or the exposure periodsin order to maximize measured time determined by the FPGA. In thisexample, the phase of the exposure periods of the activated imager issynchronized with the phase of the red light pulses of the wireless,remote light source. In an example method reduced to practice, themeasured counter value from the FPGA clock was 25,613,412. This is incontrast to the theoretical measurement of 25,600,000. This was doneusing a 24-bit counter. MOD and QUOTIENT functions from Excel can beused to calculate these values. The overflow was not found to have anegative effect on the synchronization. The measured values in theexample reduced to practice are provided in box 424 of row 422. Thismeasure was taken during a first period of time.

During a second period of time, data may not be available. For instance,the red light pulses are not detected due to a blocked light source.This may occur when an object is placed on an image-reading device, thusblocking the red light pulses from being captured by the imager. In thiscase, the latest measured value is used, such as that taken during thefirst period of time. That is, the image-reading device continues toactivate the imager and the red light source using the same phasepreviously synchronized during the first period of time when the redlight source was not blocked. An illustration of missing data due to notdetecting the red LED pulses at the photosensor during the second periodof time is provided at box 426.

The wireless synchronization can also be beneficial when additionallight sources are included with the image-reading device. The additionallight sources may be used to illuminate an area to capture images ofobjects under different light conditions. As such, it may be beneficialto activate each of the light sources at a different time or phase. Forinstance, a white light source may be included and used in combinationwith color imagers to capture images suitable for the identification ofcertain objects.

In this particular example, the top-down reader includes a white lightsource, for instance, a white LED. The white light source can beactivated based on the illumination sequence provided at row 428. Here,the white light source is activated to emit white light pulses, such aswhite light pulses 430A-430N. Timing wise, the white light pulses followthe red light pulses shown in row 404. In some cases, the white lightpulses immediately follow the red light pulses. The timing can bedetermined using the measured counter value of the FPGA clock so thatthe red light pulse timing is synchronized with the white light pulsetiming, such that the white light source is activated and providesillumination after the red light source. Said differently, thesynchronization described above between the imager of the top-downreader and the red light source of the base synchronizes the timing ofthe wireless, remote top-down reader and the base. Thus, the white lightsource of the top-down reader can be activated immediately after the redlight source of the base based on this synchronization. By synchronizingthe timing of the red and white light sources of the base and thetop-down reader, the white light source can continue to be activatedafter the red light source, even when the light from the red lightsource is blocked, such as illustrated during the second period of timein FIG. 4 . Thus, if an object is placed between the red light source onthe base and the imager at the top-down reader, the white light sourceis still activated at the correct timing following activation of the redlight source. This is done by following the previously measured valuesfor timing synchronization, such as those values measured during thefirst period of time of FIG. 4 . In synchronizing the light sources,images can be captured by one or more imagers during red illumination orwhite illumination. Where photosensors are used for the wirelesssynchronization, the timing may be synchronized between the base and thetop-down reader using the red light source (or another light source) andthe photosensor, such that the emission of the white light can followemission of the red light as described.

As previously noted, FIG. 4 is intended to be one example of wirelesstiming synchronization between light sources of a base and a top-downreader. As such, specific values suitable for use, such as configuringthe illumination to pulse at 80 Hz and the FPGA clock to measure lightpulses at 2 MHz, have been provided. It is intended that these valuesnot be limiting in any sense, and that other values could be suitable aswell. It is not practical to describe every possibility. This iscontemplated by the inventors, and as such, other suitable methods forwirelessly synchronizing light sources are intended to be within thescope of this disclosure. It is again reiterated that the wirelesssynchronization technique described with reference to FIG. 4 is only oneexample for a particular arrangement. The technique may be applied toother arrangements of one or more imagers and one or more light sourcesthat are wirelessly remote. This includes techniques for synchronizingone or more monochrome imagers in any combination with one or more colorimagers, along with one or more light sources of any color orcombination of colors.

Turning now to FIG. 5 , the figure illustrates an example timing diagram500 showing a method of wired timing synchronization between lightsources of a base and a top-down reader. While this example uses lightsources and imagers located at a base and top-down reader, it will beunderstood that the example method of wired synchronization of thesecomponents may be applicable between any imager or light source in wiredcommunication, regardless of the particular arrangement within animage-reading device. In this example, since the light sources are inconstant communication, the activation of the light sources can beperformed by a controller programmed to activate the light sources andthe imagers at particular frequencies and phases, and they willgenerally not drift out of synchronization.

In the example provided by FIG. 5 , a base includes a red light source,such as a red LED. The red light source can be activated and pulsed bythe controller at 80 Hz, which has a period of 12.5 msec. The pulsewidth (PW) is controlled and provided at 100 μs. This is just oneexample, and other PW durations may be used. The white light, emitted bythe white light source, can be controlled by the controller and emittedafter activation of the red light source. In this example, the whitelight source has the same period, but it is activated after activationof the red light source. The white light source may emit a white lightpulse having a PW that is equal to, greater than, or less than the PW ofthe red pulse. Put another way, the controller can be programmed toactivate a red light and a white light source, where the phase of theemitted red light pulses is offset the phase of the white light pulses.The controller can also be programmed to activate monochrome or colorimagers during the time in which the red and white light pulses areemitted, respectively. In some implementations, such as optical-codereading, it can be beneficial to activate the red and white lightsources simultaneously.

In the illustration provided by FIG. 5 , row 502 of timing diagram 500includes red light pulses, such as red light pulses 504A and 504B. Theillustration provides an indefinite number of red light pulses,represented as red light pulses 504A through 504N. Row 506 includeswhite light pulses, such as white light pulses 508A and 508B. Theillustration provides an indefinite number of white light pulses,represented as white light pulses 508A through 508N.

FIG. 5 , too, is intended to be one example of wired timingsynchronization between light sources of a base and a top-down reader.As such, specific values suitable for use, such as configuring the lightsources to pulse at 80 Hz and having a PW of 100 μs have been provided.It is intended that these values not be limiting in any sense, and othersuitable methods for wired synchronization of light sources are intendedto be within the scope of this disclosure.

Returning briefly to FIG. 3 , multi-mode configuration engine 300further comprises mode selector 304. Mode selector 304 generally selectsan operational mode from among a plurality of operational modes.

While various operational modes are possible, three example operationalmodes from which mode selector 304 can select will be described in moredetail. In general, however, mode selector 304 may select a mode basedon an input from a user. That is, a signal received by the controllerindicates a manual selection of an operational mode. In accordance withthe input signal, mode selector 304 selects a particular mode ofoperation.

In an aspect, mode selector 304 changes a selected mode of operation toa different mode of operation. This can occur in response to a manualinput signal, automatically in response to a particular selection event,or based on a pre-determined algorithm, further discussed below. In oneexample, mode selector 304 cycles through each operational mode in anyorder. In one case, mode selector 304 changes the selected mode ofoperation temporarily to a different operational mode, and afterperforming at least a portion of an illumination sequence or exposuresequence of the different operational mode, mode selector 304 changesthe operational mode back to the original selected mode of operation.The change can be in response to a manual input or automaticallyfollowing performance of the portion of the illumination sequence orexposure sequence. This can be beneficial when the application of theimage-reading device changes during use.

In another implementation, mode selector 304 selects a mode based on theoccurrence of a selection event. Selection events can include anintensity of ambient light compared to an illumination threshold, aspeed of an object passing through an area over which the imager isconfigured to capture the image, an object weight of an object withinthe area, detection of an object by an object detector at the area, andthe like.

For instance, a photosensor of an image-reading device detects anintensity of ambient light from light sources not included as part ofthe image-reading device. The controller is configured to have anillumination threshold. In one case, a selection event occurs if theambient light is less than the threshold illumination value.

The speed of an object passing over an area is another example selectionevent that mode selector 304 may use to select a particular operationalmode. The object passes through an area, which generally coincides withan area above the base of the image-reading device and over which animager captures an image. The controller identifies a relative speed ofthe object based on the frame-by-frame location of the object asdetermined by the imager. A selection event can occur when the speed ofthe object is greater than a threshold speed value.

Another selection event can occur based on the image-reading devicedetecting a weight of an object. As noted, some image-reading devicesinclude a scale. One location for the scale is the base of theimage-reading device. The selection event occurs when the controller ofthe image-reading device receives a signal from the scale indicating anobject weight applied to the scale. Some implementations of this comparethe object weight to a threshold weight value and provide a triggeringevent when the object weight is greater than the threshold value.Another implementation determines a length of time the weight is appliedand compares it to a timing threshold value. The selection event canoccur when the length of time is equal to or greater than the thresholdtiming value.

As noted, mode selector 304 selects an operational mode from a pluralityof operational modes. Three operational modes are described as examplesof potential operational modes from which mode selector 304 can select.These are illustrated in FIGS. 6-8 .

The various operational modes may include triggering events. Atriggering event is an occurrence that causes the controller to activatea light source or imager in a pattern corresponding to all or a portionof an illumination sequence or an exposure sequence that is defined bythe operational mode. That is, each operational mode can define anillumination sequence having timing instructions for one or more lightsources or an exposure sequence having timing instructions for exposuresby one or more imagers. Some illumination sequences and exposuresequences provide for activation of a light source or imager upon theoccurrence of the triggering event. In general, a triggering event maybe any event. The selection events previously discussed may also serveas a triggering event. Thus, while the selection event and thetriggering event may be the same event or different events, entirely,mode selector 304 uses the selection event to select a particularoperational mode, while the controller uses the triggering event as aninstruction to activate a light source or imager according to theselected operational mode.

In some aspects, a triggering event can be followed by a triggeringevent termination. One example of determining the triggering eventtermination is by predefining a number of images or a duration of timeto result after the triggering event takes place.

Turning to FIG. 6 , an example timing diagram 600 of a first operationalmode is illustrated. The first operational mode includes firstillumination sequence 602, first temporary exposure sequence 604, andfirst continuous exposure sequence 606.

As illustrated in timing diagram 600, a triggering event, such as firsttriggering event 608, can occur during operation of an image-readingdevice. First illumination sequence 602 comprises continuous activationof a light source, such as a white LED light, before first triggeringevent 608. This is illustrated using first illumination pulse lines 610,which have pulse lines occurring prior to first triggering event 608. Insome cases, such as in the example illustrated here, first illuminationsequence 602 comprises continuous activation of the light source afterfirst triggering event termination 616, illustrated by firstillumination pulse lines 610 continually provided after first triggeringevent termination 616.

Timing diagram 600 of the first operational mode further includes firsttemporary exposure sequence 604. First temporary exposure sequence 604comprises temporary activation of an imager of a camera (e.g., a colorimager associated with the white light source) to capture an image. Thisis illustrated by first temporary exposure period lines 612 beginning atthe same time, or about the same time, as first triggering event 608,continuing after first triggering event 608, and ending at the same timeas, or about the same time as, first triggering event termination 616.

Timing diagram 600 of the first operational mode can have, as analternative or additional embodiment, first continuous exposure sequence606. For instance, the first operational mode may perform onlycontinuous exposure, only temporary exposure, or both when there is morethan one imager.

First continuous exposure sequence 606 comprises continuous activationof the imager before first triggering event 608. As illustrated in FIG.6 , timing diagram 600 comprises first continuous exposure period lines614 that begin prior to first triggering event 608, continuous afterfirst triggering event 608, and continue after first triggering eventtermination 616.

Timing diagram 600 further illustrates first set of ellipses 618. Firstset of ellipses 618 is provided to illustrate that first illuminationsequence 602, first temporary exposure sequence 604, and firstcontinuous exposure sequence 606 may continue indefinitely or continueuntil there is a change in the operational mode employed by theimage-reading device.

The first operational mode may be beneficial when there is a desire forcontinuous or near-continuous image capture. One example location wherethis mode is particularly beneficial is in self-checkout lanes. Thewhite light source can be continuous, as generally no single operator isstanding at the lane for long periods of time. Further, the while lightsource serves to light the area so that customers can easily identifyand use the self-checkout lane. Given the different illuminationsequence scenarios, an imager can be used continuously to capture imagesand initiate triggering events or may be activated in response toanother triggering event. Moreover, an advantage to using the temporaryactivation of the imager is that it reduces the data that the controllerprocesses, since the data output is temporary following a triggeringevent, as opposed to the continuous imager activation aspects of thefirst operational mode.

With reference now to FIG. 7 , an example timing diagram 700 of a secondoperational mode is illustrated. The second operational mode includessecond illumination sequence 702, second dimming illumination sequence704, and second exposure sequence 706.

Similarly, a triggering event, such as second triggering event 708, canoccur during operation of an image-reading device operating in thesecond operational mode. Here, the second operational mode comprisessecond illumination sequence 702 having instructions for temporaryactivation of a light source, such as the white light source. Asillustrated by timing diagram 700, the second operational mode comprisessecond illumination pulse lines 710 that begin at the same time, orabout the same time, as second triggering event 708, continue aftersecond triggering event 708, and end the same time, or about the sametime, as second triggering event termination 716.

Timing diagram 700 further includes second dimming illumination sequence704. The second operational mode may include second dimming illuminationsequence 704, in addition to or without second illumination sequence702. That is, the second operational mode may perform only secondillumination sequence 702, perform only second dimming illuminationsequence 704, or both when there is more than one light source.

As shown in FIG. 7 , second dimming illumination sequence 704 providesfor temporary activation of the light source, and further provides for agradual decrease in intensity of the light, as illustrated by the seconddimming illumination pulse lines 712 associated with PWs of 300 μsgradually decreasing to 2 μs. This rate is just one example and otherdecreasing rates of intensity can be used. Shown in second dimmingillumination sequence 704, second dimming illumination pulse lines 712begin at the same time, or approximately the same time as secondtriggering event 708 and continue after second triggering event 708. Inthis example, the PW of the light pulses is consistent after secondtriggering event until second triggering event termination 716. Aftersecond triggering event termination 716, the intensity of the emittedlight is illustrated as decreasing using second dimming illuminationpulse lines 712 that continue after second triggering event termination716. In another sense, the intensity of the emitted light is constantduring an exposure period, such as the exposure period of secondexposure sequence 706, further discussed below, and gradually decreasesin intensity after the exposure period.

Timing diagram 700 further illustrates second exposure sequence 706 ofthe second operational mode. Here, second exposure sequence 706 providesinstructions for temporary activation of an imager to capture an image.As illustrated, second exposure period lines 714 begin at the same time,or about the same time, as second triggering event 708, continue aftersecond triggering event 708, and end at the same time, or about the sametime, as second triggering event termination 716.

In timing diagram 700, the second operational mode provides instructionsfor temporary activation of the light source that occurs simultaneouslywith the instructions for temporary activation of the imager.

Timing diagram 700 further illustrates second set of ellipses 718.Second set of ellipses 718 is provided to illustrate that secondillumination sequence 702, second dimming illumination sequence 704, andsecond exposure sequence 706 may continue indefinitely or continue untilthere is a change in the operational mode employed by the image-readingdevice.

The second operational mode also has particular benefits for variousapplications and conditions. In particular, it is beneficial forattended lanes where there is an operator present who does not wish tobe continuously exposed to the white light. It will be understood that,because the operational modes are configurable, the technology can beused for different applications and conditions. For instances, the firstoperational mode may be used when an image-reading device is used asself-checkout station. If desired, an operator may be posted at theimage-reading device. When doing so, the operator may choose to changeto the second operational mode so that the white light source isactivated when needed, and not continuously emitting white light overthe now-attended image-reading device.

Referencing now FIG. 8 , another timing diagram 800 is provided toillustrate a third operational mode. Timing diagram 800 includes thirdillumination sequence 802, third temporary exposure sequence 804, andthird continuous exposure sequence 806.

In this example, the third operational mode comprises temporaryactivation of a light source based on a triggering event and anintensity of ambient light. For instance, if the intensity of ambientlight is above an illumination threshold, then there is no activation ofthe light. This is illustrated in FIG. 8 at third illumination sequence802, showing no activation of the light, e.g., the white light source,based on third triggering event 808, as this presupposes the intensityof ambient light is greater than the illumination threshold. Where theintensity of ambient light is less than the illumination threshold,third illumination sequence 802 may appear the same as the temporaryillumination sequences of FIGS. 6-7 . Any illumination threshold may beused; however, one example illumination threshold that is suitable foruse is about 500 Lux. Thus, where ambient light is measured at about 500Lux or above, ambient illumination may be sufficient for image capturewithout active white light illumination.

Timing diagram 800 for the third operational mode further includes thirdtemporary exposure sequence 804. Third temporary exposure sequence 804comprises temporary activation of an imager to capture an image. This isillustrated by third temporary exposure period lines 812 beginning atthe same time, or about the same time, as third triggering event 808,continuing after third triggering event 808, and ending at the same timeas, or about the same time as, third triggering event termination 816.

Timing diagram 800 for the third operational mode can have, as analternative or additional embodiment, third continuous exposure sequence806. For instance, the third operational mode may perform onlycontinuous exposure, only temporary exposure, or both when there is morethan one imager.

Third continuous exposure sequence 806 comprises continuous activationof the imager before third triggering event 808. As illustrated in FIG.8 , timing diagram 800 comprises third continuous exposure period lines814 beginning prior to third triggering event 808, continuing afterthird triggering event 808, and continuing after third triggering eventtermination 816.

Timing diagram 800 further illustrates third set of ellipses 818. Thirdset of ellipses 818 is provided to illustrate that third illuminationsequence 802, third temporary exposure sequence 804, and thirdcontinuous exposure sequence 806 may continue indefinitely or continueuntil there is a change in the operational mode employed by theimage-reading device.

FIG. 8 also illustrates some of the pulse lines associated with thirdtemporary exposure sequence 804 and third continuous exposure sequence806 in bold. These pulse lines have been found to have good grey scaleand color corresponding to ambient conditions.

The third operational mode has benefits in that it might be used basedon the present conditions of the image-reading device. That is, if thereis enough ambient light, then the image-reading device is operating moreefficiently and in a more user-friendly manner by not activating thewhite light. However, as noted, since the present conditions may change,the image-reading device can be configured to switch to a differentoperational mode depending on the ambient light conditions, such as theambient light dropping to a level where it is more beneficial to haveadditional white light illuminating an area.

It will be understood that any and all combinations of the first throughthird operational modes is possible, and is intended to be within thescope of this disclosure. In one specific example, the gradual decreaseof intensity of emitted light, illustrated in FIG. 7 , can be applied toany of the operational modes. Further, while not shown, some aspects mayinclude a gradual increase in intensity after a triggering event.Activation of an imager may occur after the gradual increase inintensity stops and the intensity of the emitted light is constant. Itwill be understood that gradually increasing the intensity may be usedwith any of the operational modes where there is a temporary activationof a light source. These embodiments are also intended to be within thescope of this disclosure.

In an aspect of the technology, mode selector 304 selects an operationalmode having white illumination. Mode selector 304 selects theoperational mode using the white illumination for object recognition.

In some cases, object recognition performs well when there is bothambient light and additional active illumination. This is because of thelarge volume coverage. When using both ambient light and an activatewhite light, automatic exposure control (AEC) is beneficial. For fasterAEC, active illumination can be distributed over the whole exposureperiod (such as 10 msec).

In another aspect, when objects are swiped through the area, a narrowillumination pulse and exposure period can be used. One narrowillumination pulse example is 500 μs. Because of these scenarios, animage-reading device with real-time illumination and exposure control,such the image-reading devices described herein, is beneficial.

Two example methods that can be used to provide such lighting controlare illustrated and described with reference to FIGS. 9A-B and FIG. 10 .Using these methods, the image-reading device can provide the relativelyfaster pulses when objects are swiped through the area and longer pulsesfor object recognition.

FIG. 9A provides an example timing diagram 900 that uses hardware toprovide more than one type of peak current, such as the hardware of FIG.9B.

In timing diagram 900, ambient illumination is generally available atany given time, as illustrated in row 902. In some situations, theintensity of ambient light may vary.

As illustrated in row 904, a light source, such as an LED, can becontrolled by the controller to pulse the light source. One example isto pulse the light at a frequency of 80 Hz. These relatively shorterpulses can be used during an item detection mode, as illustrated in row906 during first portion of time 916. These shorter pulses can have a PWof 500 μs and be provided at 100 mA, for example.

Upon detecting an object over multiple pulses, as illustrated in row908, the image-reading device switches to a product recognition mode,illustrated in row 910, where it provides longer pulses. An example ofthe longer product recognition pulse is provided at row 912. One exampleis to provide the longer pulses at the same frequency as the shorterpulses. Here, this is 80 Hz. The longer pulses may be provided with a PWthat is greater than the shorter pulses. In this example, the longerpulses have a PW of 10 ms and are provided at 100 mA. This isillustrated at second portion of time 916.

The exposure sequence is provided at row 914. Here, the same exposuresequence can be provided for both object identification and objectrecognition, as illustrated at row 914. In this example, exposureperiods are provided at or between 0 and 10 ms, at 40 fps.

By providing a constant exposure sequence for both object identificationand object recognition, some aspects provide for only adjusting thelight pulses, for instance, adjusting the light pulses from relativelyshorter light pulses used for object identification and relativelylonger light pulses used for object recognition, where more light isbeneficial. This reduces the amount of light the operator is exposed to,and increases the efficiency of the image-reading device.

FIG. 9B provides circuit diagram 950 that is graphical representation ofa hardware device sufficient for controlling the light sources toperform the sequences described in timing diagram 900. The device can becontrolled through software through a logic device or processor I/O.

It can be beneficial to control the peak current of a light source indifferent scenarios. For instance, an image-reading device may use onetype of pulse for capturing images of an object moved with speed. Thatis because a relatively shorter or more narrow PW can be used to capturean object moved with speed to reduce image blur that might occur with arelatively longer light pulse or imager activation. One example of arelatively shorter or more narrow PW that can be used in this scenariois about 100 μs. To achieve this, the light pulse, e.g., LED pulse, canuse a peak current of about 1000 mA. In another scenario, items orobjects undergo a longer exposure time, which can occur when an objectis placed or rested within the field of view of an imager. Here, thelight PW, such as an LED pulse, is activated over an exposure time ofabout equal to or between 1 and 10 ms. In some cases, a peak current ofabout 1000 mA can damage the light source. In this scenario, it may bebeneficial to reduce the peak current. FIG. 9B provides an examplehardware device for achieving these currents, which can be used toimplement the illumination sequences and exposure sequences of FIG. 9A.The peak currents can be switched by controlling the M and nM shown inFIG. 9B. By controlling signal M and nM, the peak current can beswitched from a relatively higher peak current to the relatively lowerpeak current.

FIG. 10 illustrates another example timing diagram 1000. In general,timing diagram 1000 illustrates a software process for performing anillumination sequence and exposure that can be used for object detectionand object recognition. As previously discussed, there are benefits toproviding short pulses of light vs providing longer pulses of lightbased on the application of the image-reading deice, such as scanning amoving object or object recognition. In some cases, using the softwareprocess allows an image-reading device to perform the illuminationsequence without the need for additional hardware. That is, in thisparticular example, rather than use additional hardware to switch thepeak current, a controller is configured to spread multiple pulsesacross a duration of time, rather than widening the light pulse andlowering the peak current. This also has the added benefit of increasingthe speed of the AEC algorithm.

As shown in FIG. 10 , generally, ambient light is available, althoughthe intensity of the ambient light may vary. This is illustrated at row1002. For image capture using a software method, an FPGA is configuredto provide object detection and object recognition, as illustrated inrow 1004, where object detection 1010 and object recognition 1012 areperformed over first portion of time 1014 and second portion of time1016, respectively.

During first portion of time 1014 over which object detection 1010 isperformed, the FPGA is configured to pulse a light source, such as anLED. During object detection 1010, the FPGA can be configured to providea relatively shorter pulse than when performing object recognition 1012.For instance, when performing object detection 1010, FPGA could beconfigured to pulse the light source at 80 Hz with a PW of 0.5 ms.

During second portion of time 1016, over which object recognition 1012is performed, the FPGA is configured to pulse the light source atrelatively longer pulses. In some aspects, such as the one illustratedin FIG. 10 , each individual light pulse is shorter; however, the lightappears to be active for a longer time because the frequency ismodulated to a higher frequency. For instance, in the example shown,FPGA is configured to pulse a light source to have a PW of 0.05 ms. Thisis performed ten times. The illumination control is further provided bythe pulse train frequency at 80 Hz, modulated to 1 KHz

Returning to FIG. 3 , having selected an operational mode, multi-modeconfiguration engine 300 can use light activator 306 and imageractivator 308 to activate a light source and an imager.

In general, light activator 306 activates one or more light sources in apattern that corresponds to an illumination sequence of an operationalmode. Light activator 306 may activate lights using a driver, such asillumination driver 216 discussed with reference to FIG. 2 . As noted,an illumination sequence may provide instructions for activation of thelight, such as timing, PW, frequency, intensity, and the like. Lightactivator 306 provides a signal to a light source in accordance with theillumination sequence, such that the light source activates to emitlight in response to the signal.

Imager activator 308 generally operates to activate an imager of acamera to capture an image. Imager activator 308 activates one or moreimagers in a pattern corresponding to an exposure sequence provided byan operational mode. An imager may be activated when receiving imageinformation from the imager. The image information is provided from theimager as a signal based on light focused onto the imager from a lens.In one implementation, activation of the imager includes opening anaperture using a mechanical or digital shutter to allow light to focuson the imager, thereby permitting a corresponding signal from the imagerto the controller. In another implementation, activation of the imagerincludes receiving the imager information at the controller for aninstant or duration of time.

With reference now to FIG. 11 , a block diagram is provided toillustrate method 1100 for performing multi-mode illumination and imagecapture. In embodiments, one or more computer storage media havingcomputer-executable instructions embodied thereon that, when executed,by one or more processors, causes the one or more processors tooperations of method 1100. In an aspect, a controller of animage-reading device performs parts of the method.

At block 1102, an operational mode is selected. The operational mode caninclude an illumination sequence and an exposure sequence. Theoperational mode can be selected by mode selector 304. The operationalmode may be selected based on a selection event, including a manualrequest for a particular mode or an automatic selection of a mode basedon the selection event, such as an intensity of ambient light, the speedof an object, an object weight, or a predetermined algorithm. Theoperational mode may define an illumination sequence for one or morelight sources at any location of an image-reading device. Theoperational mode may define an exposure sequence for one or more imagersat any location of the image-reading device.

At block 1104, a light source is activated. The light source can beactivated by light activator 306. One or more light sources can beactivated at any location on the image-reading device. The light sourcecan be activated in a pattern corresponding to the illumination sequenceof the selected operational mode. Light activator 306 may activate alight source in accordance with the illumination sequence based on atriggering event.

At block 1106, an imager is activated. Imagers can be activated byimager activator 308. One or more imagers at any location on theimage-reading device can be activated. The imager is activated in anexposure pattern corresponding to the exposure sequence of the selectedoperational mode. Imager activator 308 may activate an imager inaccordance with the exposure sequence based on the triggering event.

Illumination Scheme for Capturing Monochrome, Color, and Ambient LightImages

As previously described, another aspect of the technology that improvesupon conventional image-reader devices provides for a light pulsesequence that takes advantage of red light, white light, and ambientlight. The light pulse is provided in a repeating pattern, where eachpulse sequence may include a combination of red, white, and ambientlight. The pulses can be provided at a frequency rate that does notpermit the human eye to perceive the individual pulses or the variouslight provided by the different pulses. Imagers can be activated acrossvarious locations of an image-reading device that are timed according toa specific wavelength or light color within the pulse. For instance, aparticular imager may be activated with a particular light source, suchas color image sensors with white illumination sources and monochromesensors with red illumination sources. Thus, different images can becaptured of an object by different imagers using various lightingwithout having to change the lighting pattern that the operatorexperiences.

Taking images using various wavelengths of light is beneficial, as somewavelengths, e.g., some colors schemes, are better for particularapplications. For instance, red light is good for quick reading ofoptical codes or object detection within an area, and red light itselfis not harshly perceived by an operator. A short white light pulse, ormore generally multi-spectrum light pulses, can also be used for opticalcode reading. A longer white light pulse is beneficial for objectrecognition. Ambient light is beneficial for reading objects that arereflective or glossy, such as a clear plastic or the screen of a mobiledevice.

FIG. 12 provides timing diagram 1200 illustrating a repeating series oflight pulses and exposure periods. In timing diagram 1200, each lightpulse is formed of different wavelengths or colors, including red,white, or ambient light. As illustrated in FIG. 12 , timing diagram 1200includes row 1212 that illustrates light pulses 1202A and 1202Bextending forward in time from left to right, as illustrated on axis1203.

As will be further discussed, timing diagram 1200 also illustrates fourcases of exposure timing. Row 1214 illustrates exposure case one. Row1216 illustrates exposure case two. Row 1218 illustrates exposure casethree. Row 1220 illustrates exposure case four. Each of the exposurecases provides an exposure sequence indicating the activation of animager during an exposure period, as will be further discussed.

Both the light pulses and the exposure cases are illustrated as arepeating series using set of ellipses 1222.

Regarding light pulses 1202A and 1202B, each light pulse includes asequence of red, white, and ambient light, as illustrated in lightpulses 1202A and 1202B, using illumination key 1224. The sequenceprovided by light pulses 1202A and 1202B is an example. It will beunderstood that other sequences may be formed using red, white, andambient light. Such sequences are intended to be within the scope ofthis disclosure.

In general, an image-reading device may form light pulses by activatinglight sources in a specific pattern. Thus, to form light pulses 1202Aand 1202B, a red light source is activated for specified amount of time.This forms red portion 1204A, extending from T₀ 1226A to red actual/max₀1228A. The image-reading device stops activation of the red light, e.g.,deactivates the red light, at time red actual/max₀ 1228A.

At time red actual/max₀ 1228A, image-reading device activates a whitelight source for a specified amount of time. Here, the white lightsource is active over time red actual/max₀ 1228A to time BCR (BarcodeReading) white actual₀ 1230A, when image-reading device stops activationof the white light source. This forms first white portion 1206A.

To form ambient portion 1208A, image-reading device may not activateanother light source during time BCR white actual₀ 1230A to OID (objectidentification) white max₀ 1236A. Thus, in effect, light pulse 1202Aincludes ambient portion 1208A, extending from time BCR white actual₀1230A to OID white max₀ 1236A. Ambient portion 1208A can be greaterthan, e.g., have a longer duration than, second white portion 1210A.

At time OID white max₀ 1236A, the white light source is activated toform second white portion 1210A. Activation of the white light isstopped at or prior to time T₁ 1226B, forming second white portion1210A.

In an example reduced to practice, red light illumination to form redportion 1204A occurs for about 100 μs; white light illumination to formfirst white portion 1206A occurs for about 100 μs; no illumination toallow for ambient portion 1208A occurs for about 6 ms; and white lightillumination to form second white portion 1210A occurs for about 3 ms.In an example where red light pulses 1202A and 1202B are pulsed at afrequency of 80 Hz, the total time duration of red portion 1204A, firstwhite portion 1206A, ambient portion 1208A, and second white portion1210A may be equal to or less than 12.5 ms.

The sequence having red portion 1204A, first white portion 1206A,ambient portion 1208A, and second white portion 1210A can be repeated.One method of repeating this sequence is to activate the red and whitelight sources at the same frequency. It may be beneficial to usefrequencies above 60 Hz so that a human operator does not perceiveflashing. For most people, frequencies above 60 Hz will blend together,making the light pulses less bothersome, and it's more likely that theoperator will acclimate to, what is perceived as, a fluid light pattern.In one example, 80 Hz is used to time the activation of the lights. Indoing so, the sequence is repeated, as illustrated in light pulse 1202B,having red portion 1204B, first white portion 1206B, ambient portion1208B, and second white portion 1210B. As illustrated by set of ellipses1222, the pulses are repeated having this sequence. In one example, thetime from T₀ 1226A to T₁ 1226B is about 16 ms, which can be used with a60 Hz frequency. In another example, the time from T₀ 1226A to T₁ 1226Bis about 12 ms, which can be used with an 80 Hz frequency.

As illustrated, light pulses 1202A and 1202B respectively include firstwhite portion 1206A and second white portion 1210A, and first whiteportion 1206B and second white portion 1210B. When activating the whitelight source to form the white portions, the white light source can beactivated to have a gradual increase in intensity or gradual decrease inintensity. Any combination of these can be performed in this sequence.That is, first white portions 1206A and 1206B can include a gradualincrease in intensity, a gradual decrease in intensity, or both.Similarly, second white portions 1210A and 1210B can include a gradualincrease in intensity, a gradual decrease in intensity, or both. Any andall combinations are contemplated. Moreover, the gradual increase mayoccur prior to or at the activation times indicated. That is, whenoccurring prior the activation time, the intensity of the white lightcan be increased until constant at the activation time. Similarly, thegradual decrease can begin prior to or at the times indicated forstopping activation of the white light. Any and all combination arecontemplated and are intended to be within the scope of this disclosure.

One benefit of placing ambient portion 1208A between first white portion1206A for BCR white illumination and second white portion 1210A for OIDwhite illumination allows exposures to aggregate both white and ambientin one imager exposure. For instance, first white portion 1206A may growinto ambient portion 1208A. Similarly, second white portion 1210A wouldgrow “backwards” into ambient portion 1208A. The combination of whiteand ambient light allows good visibility of the object in question (dueto the white illumination) and good visibility of the surrounding scene(due to the presence of ambient light, e.g. ambient “illumination”).

Further, one or more of red light sources and one or more of white lightsources can be used to form the repeating series. Each of these lightsources can be located anywhere on the image-reading device. Forinstance, a red light source can be located at a horizontal portion of abase, a vertical portion of the base, or at a top-down reader. Likewise,a white light can be located at the horizontal portion of a base, thevertical portion of the base, or at the top-down reader. Allcombinations are intended to be within the scope of this disclosure. Inone specific embodiment, a red light source is located at the base, anda white light source is located at the top-down reader and emits whitelight over an area of the base.

As previously described, the image-reading device can have one or moreimagers positioned at any location, including imagers located in thebase and imagers located in the top-down reader. In an aspect, eachimager can be configured, or utilized, to capture an image for aspecific application. For instance, an imager may be activated for anexposure period to capture an image during a specific portion of a lightpulse, such as light pulses 1202A and 1202B.

Some example exposure sequences for imager activation are illustrated intiming diagram 1200, and are provided as exposure cases one throughfour.

At row 1214, case one provides for a first imager activation overexposure period 1240 from time T₀ 1226A to time red actual/max₀ 1228A.First exposure period 1240 may coincide with red light activation thatforms red portion 1204A. In an example, first exposure period 1240 isabout 100 μs. A dedicated imager located on the base or the top-downreader of the image-reading device can be activated during the firstexposure period 1240. This imager can be used to return an image forreading a barcode, such as paper barcode or another barcode notpresented on a display device or a glossy surface. The image from thisimager can also be used for Digital Water Mark (DWM) reading.

At row 1216, case two provides for a second imager activation oversecond exposure period 1242 from time red actual/max₀ 1228A to time BCRwhite actual₀ 1230A. Second exposure period 1242 may coincide with whitelight activation that forms first white portion 1206A. In an example,second exposure period 1242 is about 100 μs. A dedicated imager locatedon the base or the top-down reader of the image-reading device can beactivated for second imager activation during second exposure period1242. This imager can be used to return an image for reading a barcode,such as paper barcode or another barcode not presented on a displaydevice or a glossy surface. The image from this imager can also be usedfor monochrome DWM reading. The image can also be used for color imagecapture used for security and object identification.

At row 1218, case three provides for a third imager activation duringthird exposure period 1244 from time OID white max₀ 1236A to time OIDwhite actual₀ 1238A. Third exposure period 1244 may coincide with all ora portion of white light activation that forms second white portion1210A. In an example, third exposure period 1244 is at or less than 3ms. In an aspect, third exposure period 1244 is about 1.5 ms. In anotheraspect, third exposure period 1244 is about 1 ms. A dedicated imagerlocated on the base or the top-down reader of the image-reading devicecan be activated for the third imager activation during third exposureperiod 1244. This imager can be used for color image capture forsecurity and object identification. In particular, the relatively longerexposure period during active illumination of white light is beneficialfor object recognition, and as such, the image returned from the thirdimager activation is generally suitable for object recognition.

At row 1220, case four provides for a fourth imager activation duringfourth exposure period 1246 from time ambient actual₀ 1234A to time OIDwhite max₀ 1236A. Fourth exposure period 1246 may coincide with all or aportion of ambient portion 1208A. In an example, fourth exposure period1246 is about 1 ms. A dedicated imager located on the base or thetop-down reader of the image-reading device can be activated for thefourth imager activation. This imager can be used to capture an imagefor reading optical codes on reflective or glossy surfaces, or thosedisplayed on a display device of a mobile device.

In general, imagers, such as those described with reference to cases onethrough four, are activated to capture an image in repeating series.This is illustrated using set of ellipses 1222. One example method foractivating imagers is to activate each imager using the same frequency,adjusted by the timing to correspond with a particular portion of thelight pulses over which the image is configured to activate. In thisway, the frequencies under which the imagers are activated, i.e., theframerate frequency of the imager, are offset from one another. That is,the frequency of each imager is the same, while the exposure period ofthe imager occurs during a different time of each frequency cycle.

The imagers can be configured to activate at a frequency half that ofthe frequency used for the illumination. That is, the illuminationfrequency is two times the framerate frequency of the imagers. Forexample, if the frequency for activating the light sources is providedat 80 Hz, then the frequency for imager activation can be configured to40 Hz. Likewise, if the frequency for activating the light sources isprovided at 60 Hz, then the frequency for imager activation can beconfigured to 30 Hz. Thus, imagers would activate for every second lightpulse. As illustrated, in timing diagram 1200, no imager activation isshown associated with light pulse 1202B. However, the imager activationprovided by cases one through four would also occur for the light pulsefollowing light pulse 1202B, and so on for every other light pulse.

In some cases, light sources and imagers are located in differentlocations of the image-reading device, including the base and a top-downreader. To provide the light pulses and activate the imagers atdifferent times, the various light sources and imagers can besynchronized. Previously discussed synchronization methods can be used.

Any combination of cases may be used when operating the image-readingdevice. For instance, case one can be used with any combination of casestwo through four, and case two could be used with any combination ofcases one, three, and four, and so forth. Each case may be used alone orin use with one additional case, two additional cases, or all three.While cases one through four of timing diagram 1200 are discussed andillustrated in a particular order, no specific order of imageractivation as part of the various cases is implied. In operation, anyexposure order using more than one imager can be performed. In anotherexample, a portion of the imagers are activated during a first lightpulse, while another portion is activated during a second light pulse,and each of the activated imagers continues to be activated every otherlight pulse. The first portion and second portion are activated offsetby one light pulse.

In an aspect of the technology, the repeating pulse sequence is used inconjunction with multi-mode illumination and image capture, which hasbeen previously discussed. For instance, repeating pulse sequences, suchas those provided in timing diagram 1200 and previously discussed, maybe used with any of the operational modes when using a multi-modeconfiguration of the image-reading device.

With reference now to FIG. 13 , a block diagram is provided toillustrate method 1300 for performing illumination and exposure using arepeating series of light pulses having a sequence of red, white, anambient light. In embodiments, one or more computer storage media havingcomputer-executable instructions embodied thereon that, when executed,by one or more processors, cause the one or more processors to performoperations of method 1300. In an aspect, a controller of animage-reading device performs operations of the method.

At block 1300, one or more light sources are activated to emit arepeating series of light pulses. The repeating series of light pulsesmay comprise portions of red and white active illumination and a portionof ambient light. In a specific example, each of the pulses includes afirst portion of red light, a second portion of white light, a thirdportion of ambient light, and a fourth portion of white light. Thesecond portion of white light and the fourth portion of white light canbe separated by the third portion of ambient light. In cases, the firstportion of white light can be provided with a shorter PW than the thirdportion of white light. Each of the red and white light portions of thelight pulses may be emitted by different light sources. In some cases,the white light portions are emitted by the same or a different whitelight source.

At block 1304, a first imager is activated during a first exposureperiod. The first exposure period may occur during emission of the redlight, white light, or ambient light. That is, the first exposure periodmay occur during the first portion of red light, the second portion ofwhite light, the third portion of ambient light, or the fourth portionof white light.

At block 1306, a second imager is activated during a second exposureperiod. The second exposure period is different from the first. Thesecond exposure period may be offset from the first exposure period.That is, the first exposure period and the second exposure period can beprovided at the same frequency, while each repeatedly occurring at adifferent time. For instance, the first exposure period may coincidewith any of the red light, white light, or ambient light portions, whilethe second exposure period coincides with any of the red light, whitelight, or ambient light portions that are different from the portioncoinciding with the first exposure period.

This may continue for any number of imagers and exposure periods. Forinstance, a third imager could be activated during a third exposureperiod. The third exposure period is different from the first exposureperiod and the second exposure period. The third exposure period can beoffset from the first exposure period and the second exposure period.The third exposure period can coincide with any of the red light, whitelight, or ambient light portions different from the portions coincidingwith the first and second exposure periods. This can continue any numberof times. One benefit of a third imager and a third exposure period isthat, collectively, the three imagers can capture an image under each ofthe different conditions, e.g., red, white, and ambient lightingconditions. In effect, this allows a nearly instant mechanism to capturean image that can be used for three different applications without theoperator having to engage in multiple scans, while at the same time,providing a single light type and sequence from the perspective of theoperator.

CONCLUSION

The subject matter of the present technology is described withspecificity herein to meet statutory requirements. However, thedescription itself is not intended to limit the scope of thisdisclosure. Rather, the inventors have contemplated that the claimed ordisclosed subject matter might also be embodied in other ways, toinclude different steps or combinations of steps similar to the onesdescribed in this document, in conjunction with other present or futuretechnologies. Moreover, although the terms “step” or “block” might beused herein to connote different elements of methods employed, the termsshould not be interpreted as implying any particular order among orbetween various steps herein disclosed unless and except when the orderof individual steps is explicitly stated.

Words such as “a” and “an,” unless otherwise indicated to the contrary,include the plural as well as the singular. Thus, for example, theconstraint of “a feature” is satisfied where one or more features arepresent. Also, the term “or” includes the conjunctive, the disjunctive,and both (a or b thus includes either a or b, as well as a and b).

The use of the term “about” throughout this disclosure means±10%.

Embodiments described above may be combined with one or more of thespecifically described alternatives. In particular, an embodiment thatis claimed may contain a reference, in the alternative, to more than oneother embodiment. The embodiment that is claimed may specify a furtherlimitation of the subject matter claimed.

From the foregoing, it will be seen that this technology is one welladapted to attain all the ends and objects described above, includingother advantages that are obvious or inherent to the structure. It willbe understood that certain features and subcombinations are of utilityand may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims. Since many possible embodiments of the described technology maybe made without departing from the scope, it is to be understood thatall matter described herein or illustrated the accompanying drawings isto be interpreted as illustrative and not in a limiting sense.

Some example aspects of the technology that may be practiced from theforgoing disclosure include the following:

Aspect 1: A computerized method of multi-mode illumination and imagecapture, the method comprising: receiving an input signal in response toa trigger event, the input signal identifying an operational mode from aplurality of operational modes, the operational mode being determinedbased on the trigger event, each operational mode defining anillumination sequence and an exposure sequence; activating a lightsource in an illumination pattern corresponding to the illuminationsequence of the identified operational mode; activating an imager tocapture an image, the imager activated in an exposure patterncorresponding to the exposure sequence of the identified operationalmode.

Aspect 2: Aspect 1, wherein the trigger event is based on an intensityof ambient light, and wherein the operational mode provides foractivation of the light source based on the light source emitting whitelight, the operational mode being determined based on the intensity ofambient light compared to illumination threshold.

Aspect 3: Any of Aspects 1-2, wherein the event trigger is based on aspeed of an object moving through an area from which the image iscaptured.

Aspect 4: Any of Aspects 1-3, wherein activating the light sourcefurther comprises gradually increasing an intensity of light emittedfrom the light source and gradually decreasing the intensity of thelight emitting from the light source.

Aspect 5: Any of Aspects 1-4, wherein the exposure sequence comprisesimager activation over a first period of time and the illuminationsequence comprises light source activation over the first period oftime, the illumination sequence further comprising gradually decreasingan intensity of light emitted from the activated light source over asecond period of time following the first period of time.

Aspect 6: An image-reading device for multi-mode illumination and imagecapture comprising: a first light source; a first imager configured tocapture an image of an area; and a controller comprising at least oneprocessor and computer storage media, the computer storage media havingstore thereon computer-readable instructions that, when executed by theat least one processor, cause the at least one processor to: select anoperational mode defining an illumination sequence and an exposuresequence; activate the first light source in an illumination patterncorresponding to the illumination sequence of the selected operationalmode; and activate the first imager in an exposure pattern correspondingto the exposure sequence of the selected operational mode.

Aspect 7: Aspect 6, wherein the operational mode is selected from: afirst operational mode comprising a first illumination sequence havingcontinuous activation of the first light source before a firsttriggering event and a first exposure sequence having continuousactivation of the first imager before the first triggering event; asecond operational mode comprising a second illumination sequence havingtemporary activation of the first light source after a second triggeringevent and a second exposure sequence having temporary activation of thefirst imager after the second triggering event; and a third operationalmode comprising a third illumination sequence having temporaryactivation of the first light source after a third triggering event andbased on an intensity of ambient light, and a third exposure sequencehaving temporary activation of the first imager after the thirdtriggering event.

Aspect 8: Any of Aspects 6-7, wherein temporary activation of the firstlight source after the third triggering event of the third operationalmode is based on the intensity of ambient light detected by theimage-reading device being less than an illumination threshold.

Aspect 9: Any of Aspects 6-8, further comprising a base, wherein thefirst light source is a top-down light source configured to emit lightproximate the base, and wherein the area corresponds to the base and thefirst imager is configured to capture the image of the areacorresponding to the base.

Aspect 10: Any of Aspects 6-9, further comprising a second light sourceand a second imager, the first light source configured to emit redlight, the second light source configured to emit white light, the firstimager being a monochrome imager, the second imager being a colorimager, wherein the controller activates the first light source to emitred light while simultaneously activating the monochrome imager, andwherein the controller activates the second light source to emit whitelight while simultaneously activating the color imager.

Aspect 11: Any of Aspects 6-10, further comprising synchronizing thefirst light source with the first imager by maximizing a time duringwhich the first imager detects light emitted by the first light source.

Aspect 13: Any of Aspects 6-12, wherein the time is maximized byadjusting a phase of the first light source or the first imager.

Aspect 14: Computer storage media having stored thereoncomputer-readable instructions that, when executed by a processor, causethe processor to perform operations of multi-mode illumination and imagecapture, the operations comprising: selecting an operational mode for alight source of an image-reading device from among a plurality ofoperational modes, each operational mode defining an illuminationsequence for the light source and an exposure sequence for an imager,the plurality of operational modes including: a first operational modecomprising a first illumination sequence having continuous activation ofthe light source before a first triggering event and a first exposuresequence having continuous activation of an imager before the firsttriggering event; a second operational mode comprising a secondillumination sequence having temporary activation of the light sourcebefore a second triggering event and a second exposure sequence havingtemporary activation of the imager after the second triggering event;and a third operational mode comprising a third illumination sequencehaving temporary activation of the light source after a third triggeringevent and based on an intensity of ambient light, and a third exposuresequence having temporary activation of the imager after the thirdtriggering event; activating the light source in an illumination patterncorresponding to the illumination sequence of the selected operationalmode in response to a triggering event; and activating the imager tocapture an image, the imager activated in an exposure patterncorresponding to the exposure sequence of the selected operational modein response to the triggering event.

Aspect 15: Aspect 14, wherein the operational mode is selected based onat least one of the intensity of ambient light, a speed of an objectpassing through an area over which the imager is configured to capturethe image, or an object weight of an object within an area over whichthe imager is configured to capture the image.

Aspect 16: Any of Aspects 14-15, wherein the third exposure sequencecomprises imager activation over a first period of time and the thirdillumination sequence comprises light source activation over the firstperiod of time, the illumination sequence further comprising graduallydecreasing an intensity of light emitted from the activated light sourceover a second period of time following the first period of time.

Aspect 17: Any of Aspects 14-16, wherein activating the light sourceincludes gradually increasing an intensity of light emitted from thelight source and gradually decreasing the intensity of light emittedfrom the light source.

Aspect 18: Any of Aspects 14-17, further comprising changing theselected operational mode to a different mode of operation in responseto receiving a manual input signal.

Aspect 19: Any of Aspects 14-18, further comprising automaticallychanging from the different mode of operation to the selectedoperational mode after performing the illumination sequence and theexposure sequence of the different mode of operation.

Aspect 20: Any of Aspects 14-19, wherein each illumination sequencecomprises a repeating series of light pulses, each light pulsecomprising a portion of emitted red light, a portion of emitted whitelight, and a portion of ambient light.

Aspect 21: Any of Aspects 14-20, wherein the each exposure sequencecomprises an exposure period during which the imager is activated, theexposure period occurring during one of the portion of emitted redlight, the portion of emitted white light, or the portion of ambientlight.

Aspect 22: A computer-implemented method of illumination and exposure,the method comprising activating one or more light sources to emit arepeating series of light pulses, each light pulse comprising red light,white light, and ambient light; activating a first imager during a firstexposure period, the first exposure period occurring during emission ofonly the red light, the white light, or the ambient light; andactivating a second imager during a second exposure period differentthan the first exposure period, the second exposure period occurringduring emission of only the red light, the white light, or the ambientlight.

Aspect 23: Aspect 22, wherein each light pulse comprises a first portionof red light, a second portion of white light, a third portion ofambient light, and a fourth portion of white light, the second portionof white light and the fourth portion of white light separated by thethird portion of ambient light.

Aspect 24: Any of Aspects 22-23, wherein the fourth portion of whitelight comprises a decreasing intensity.

Aspect 25: Any of Aspects 22-24, wherein the one or more light sourcesare activated at an illumination frequency, the illumination frequencybeing two times greater than both a first frame rate frequency of thefirst imager and a second frame rate frequency of the second imager.

Aspect 26: Any of Aspects 22-25, wherein the first frame rate frequencyof the first imager is offset from the second frame rate frequency ofthe second imager.

What is claimed is:
 1. An image-reading device for multi-modeillumination and image capture comprising: a first light source; a firstimager configured to capture an image of an area; and a controllercomprising at least one processor and computer storage media, thecomputer storage media having stored thereon computer-readableinstructions that, when executed by the at least one processor, causethe at least one processor to: select an operational mode from among aplurality of different operational modes, each operational mode definingan illumination sequence for the first light source and an exposuresequence for the first imager; activate the first light source in anillumination pattern corresponding to the illumination sequence of theselected operational mode; and activate the first imager in an exposurepattern corresponding to the exposure sequence of the selectedoperational mode, wherein the plurality of operational mode includes afirst operational mode associated with object detection includingreading optical codes, and a second operational mode associated withobject recognition is selected based on an object weight of an objectwithin an area over which the imager is configured to capture the image.2. The image-reading device of claim 1, further comprising a basescanner and a top-down imaging device, wherein the top-down imagingdevice includes the first light source configured to emit light from atop-down view toward the base, and the first imager configured tocapture the image of the area from a top-down view toward the base, andwherein the base scanner includes a second light source and a secondimager, wherein the controller activates the first light source to emita first wavelength while simultaneously activating the first imager, andwherein the controller activates the second light source to emit asecond wavelength while simultaneously activating the second imager. 3.The image-reading device of claim 2, wherein synchronization for thetop-down imaging device relative to the base scanner include the firstimager and the first light source being programmed according to aparticular timing sequence relative to a timing sequence for the basescanner.
 4. The image-reading device of claim 1, wherein the at leastone processor is configured to adjust a pulse width of the first lightsource such that the pulse width for the first light source is shorterduring a first operational mode and longer during a during a secondoperational mode.
 5. The image-reading device of claim 4, wherein afrequency for the pulses of the first light source is the same duringthe first operational mode and the second operational mode.
 6. Theimage-reading device of claim 4, wherein a frequency for the pulses ofthe first light source is different during the first operational modeand the second operational mode.
 7. The image-reading device of claim 4,wherein the exposure pattern for the first imager is the same during thefirst operational mode and the second operational mode.
 8. Theimage-reading device of claim 1, wherein the selection is based on theweight being greater than a predetermined threshold value.
 9. Theimage-reading device of claim 1, wherein the selection is based on alength of time the weight is applied being greater than a predeterminedtiming value.
 10. The image-reading device of claim 1, wherein selectionbetween at least some of the plurality of operational modes is based ona manual selection by a user.
 11. The image-reading device of claim 1,wherein selection between at least some of the plurality of operationalmodes is based on a determined speed of the object from a frame-by-framelocation of the object determined by the first imager.